"Life, using matter to express itself in bodily shape, first traces a geometrical pattern. From the lowest form in crystals, upwards to more complicated patterns in the higher organisations--there is always first this geometrical pattern as skeleton. For geometry lies at the root of all possible phenomena; and is the mind's interpretation of a living movement towards shape that shall express it." He brought his eyes closer to the other, lowering his voice again. "Hence," he said softly, "the signs in all the old magical systems--skeleton forms into which the Powers evoked descended; outlines those Powers automatically built up when using matter to express themselves. Such signs are material symbols of their bodiless existence. They attract the life they represent and interpret. Obtain the correct, true symbol, and the Power corresponding to it can approach--once roused and made aware. It has, you see, a ready-made mould into which it can come down." "Once roused and made aware?" repeated Henriot questioningly, while this man went stammering the letters of a language that he himself had used too long ago to recapture fully. "Because they have left the world. They sleep, unmanifested. Their forms are no longer known to men. No forms exist on earth to-day that could contain them. But they may be awakened," he added darkly. "They are bound to answer to the summons, if such summons be accurately made." "Evocation?" whispered Henriot, more distressed than he cared to admit. Vance nodded. Leaning still closer, to his companion's face, he thrust his lips forward, speaking eagerly, earnestly, yet somehow at the same time, horribly: "And we want--my aunt would ask--your draughtsman's skill, or at any rate your memory afterwards, to establish the outline of anything that comes." He waited for the answer, still keeping his face uncomfortably close. Henriot drew back a little. But his mind was fully made up now. He had known from the beginning that he would consent, for the desire in him was stronger than all the caution in the world. The Past inexorably drew him into the circle of these other lives, and the little human dread Vance woke in him seemed just then insignificant by comparison. It was merely of To-day. "You two," he said, trying to bring judgment into it, "engaged in evocation, will be in a state of clairvoyant vision. Granted. But shall I, as an outsider, observing with unexcited mind, see anything, know anything, be aware of anything at all, let alone the drawing of it?"